1. Field of the Invention
The present invention relates to a trailer hitch assembly and more particularly to an elongate receiver tube for a trailer hitch assembly and a method of making the same.
2. Description of the Prior Art
Trailer hitches employed in conventional motor vehicles include a receiver tube permanently affixed to the motor vehicle and is adapted to receive a removable trailer hitch bar. The receiver tube is typically affixed to the vehicle frame and may include additional cross bracing. The exposed end of the receiver tube is open to receive the removable trailer hitch bar. A mounting ball adapted to receive a trailer tongue is typically mounted on the exposed end of the trailer hitch bar.
The exposed end of the receiver tube is exposed to considerable lateral and up and down forces during use. In order to compensate for these forces, the ends of the receiver tubes have been reinforced. Such reinforcement includes the use of a reinforcement ring which is slid over the end of the receiver tube end and welded in place. Such a welded construction includes a weld bead which is a corrosion site adversely affecting the life cycle of the assembly.
Another method has been developed wherein the trailer hitch receiver tube end was reinforced by a metal forming process. The process is carried out with a tube stock at an elevated temperature of about 1800xc2x0 F. and was upset to form a reinforcement bead around the entire peripheral of the tube. The process is referred to as a xe2x80x9chot upsetxe2x80x9d operation.
It is an object of the present invention to produce an elongate receiver tube wherein the exposed end is reinforced by a cold forming process to form a crimped reinforcement flange thereon.
Another object of the invention is to produce a method for cold forming a crimped flange on the end of the elongate receiver tube for a trailer hitch assembly.
The above, as well as other objects and advantages of the invention may be readily achieved by an elongate receiver tube and method for making the same wherein the elongate receiver tube for a trailer hitch assembly comprises an elongate tube having an internal rectangular cross-section and having one end adapted to receive a trailer hitch bar having a complimentary outer rectangular cross-section, the one end of the tube having an integral reinforcement construction wherein the end of the tube is provided with an outwardly extending fold formed of two thicknesses of the tube including the outermost end portions are folded against one another by a cold forming process to form a peripheral outwardly extending fold at the end of the tube, the fold having an inner dimension which is the same as the inner dimension of the tube and an outer dimension greater then the outer dimension of the tube.